Reserve parachutes have been used as a back-up parachute to an original main parachute. When reserve parachutes were initially used, however, they would routinely become entangled with a malfunctioned main parachute. A method was then developed so that the jumper could release (i.e. cut-away) the malfunctioned main parachute prior to deploying the reserve parachute. However, this introduced a new drawback of loss of time and altitude after cut-away of the main parachute for the reserve parachute to then fully deploy. To decrease the reserve deployment time/altitude requirements after cut-away of the main parachute, a Reserve Static Line (RSL) was introduced, with one end connected to the main parachute riser(s) and the other end attached to a reserve ripcord pin that deploys the reserve parachute. Upon cut-away of the main parachute, as the jumper falls away, the RSL is pulled taut and removes the reserve ripcord pin, causing the reserve pilot chute to be released and deploy the reserve parachute.
Although the RSL reduced the time and altitude to pull the reserve ripcord pin, it did not reduce the actual deployment time/attitude of the reserve parachute, once the reserve parachute container is opened.